1. Field of the Invention
This invention relates to a device for controlling the position of objects on the display of a computer system, and more particularly, to an improved control device for manipulating such objects while preventing rotation which causes skewed movement of such objects.
2. Art Background
Standard control devices for manipulating the position of objects on the display screen of a computer system include cursor positioning keys, mouse systems, track balls and joy sticks. With a mouse, the movement of the mouse across a pad translates to the movement of a cursor or other object across the computer display screen in the same direction in most circumstances. Similarly, the rotation of a trackball, while remaining in place, creates an equivalent movement of a cursor, or the like, across the computer display screen.
Many computer users, being right handed or left handed, have a tendency or preference to angle their writing hand inward toward their body. Thus, depending upon the positioning of the trackball or mouse pad, a straight wrist position may be uncomfortable or awkward. However, this straight wrist position is essential for proper movement of the object across the screen. If the wrist is turned inward so that the mouse is not positioned perpendicular to it's x and y axes when in the mouse is not positioned perpendicular to it's x and y axes when in use, the cursor will travel in an angled or skewed movement across the screen. For example, if the cursor is turned 30.degree. inward toward the user's body, and then the mouse is moved in a line parallel to the direction the user is facing, the cursor will move at an angle across the computer screen 30.degree. from vertical.
For graphic artists who may use a computer to draw pictures and the like, the angling of the wrist may be important for the drawing techniques or styles which they use. For example, in using paint brushes, colored pencils, chalk or charcoal, sometimes the artist angles his or her wrist to create the desired brush stroke or the like. However, if the artist were to angle the wrist while using a prior art mouse, the line would not go where the mouse goes, but would go at an angle instead. Also, for all users, there is a natural tendency to curl inward the wrist toward the body, whether with the right or left hand.
There is a prior art device called a pantagraph which has been used in the graphics industry for a number of years to trace and enlarge a picture, drawing or the like. The device consists of a pointer which is coupled through a connector to a pen, where the coupling mechanism enable the enlargement of the image traced by the pointer. These pantagraph devices have not heretofore been adapted for any use on a computer system.